Most people develop a generic way of acknowledging others, it's not personal. I do it myself with a lot of clients and it's something I developed over the years where it's an acknowlegement that is not intended to go deep into another person. There were weekends where I would meet four hundred people easy. So no way could I be more in depth, but I did have to develop a way of acknowledging.

So this woman saying "you do the jobs that others won't do" is meant to help you feel important, it's her generic. You mentioned she doesn't really know you personally, when that's the case you are dealing with some kind of generic acknowledgement to show appreciation.